The snow has blown northeast over Long Island and out to sea – but the frigid arctic air from the Polar Vortex isn’t going anywhere soon.

Temperatures bottomed out at 9 degrees in New York City overnight after nearly a foot of snow fell in Central Park, and Wednesday’s highs will only be about 15 degrees in the city and colder in the suburbs, with wind chills in the single digits or lower.

“Just some light snow lingered in eastern Long Island early on Wednesday; otherwise, the snowstorm had ended, but a blast of cold air will stay through the end of the week,” meteorologist Courtney Spamer said on AccuWeather.com.

“Frigid weather will continue through the balance of the week with highs barely reaching 20 degrees.”

Many school districts in the tri-state area were closed or had delayed openings – including the city’s Catholic schools – although city public schools were open, frustrating many parents and kids.

“I don’t know how the Chancellor and the Mayor can live with themselves right now. This is disgusting. YOU ARE PUTTING PEOPLE’S LIVES AT RISK,” griped Maureen Rahill-Comin on the Department of Education’s Facebook page.

“My child is staying home today but there are people who have lost the option to put their own safety first. Please bombard the Mayor’s office and the chancellors office with messages expressing your outrage,” she wrote.

“You are crazy if you think I’m going to school today! “ added student Afsana Akter.

The Wildlife Conservation Society said the Bronx Zoo, Central Park Zoo, Prospect Park Zoo, Queens Zoo and the New York Aquarium will open at 11 a.m. Wednesday, an hour later than usual, because of the snow and slippery roads.

LIRR trains was operating on a weekend schedule and was experiencing delays due to drifting snow and higher accumulations.

Metro-North was on a regular weekday scheduled but many trains were delayed and a few were cancelled due to the weather.

More than 1,500 flights had been cancelled as of 8:30 a.m. nationwide, including 190 at laGuardia, 124 at Kennedy and 157 at Newark, according to FlightAware.com.

Many residents said Mayor de Blasio bungled the second winter storm of his administration when the snow hit a few hours earlier than expected Tuesday — causing a rash of car crashes and snarling traffic across the city.

On Tuesday, the flakes began to fall at around 8 a.m., and sanitation trucks were slow to hit the streets and spread enough salt to keep them passable.

They largely ignored the well-heeled Upper East Side until nearly 5 inches fell — according to the city’s PlowNYC Web site — and by then, buses were stranded and people could barely cross the streets.

“I can’t believe de Blasio could do this. He is putting everyone in danger,” said Barbara Tamerin, 70, who had to use snowshoes and ski poles to navigate the street. “What is he thinking? I can barely get around — and I’m on snowshoes!”

“The Upper East Side did not vote for [de Blasio],” said lifelong resident Molly Jong Fast, daughter of famed novelist Erica Jong.

She said de Blasio “is trying to get us back.”

In other storm-related chaos:

A parade of idled buses with lighted “Not In Service” signs stretched down Lexington Avenue for three blocks because the lead bus got stuck in the snow near East 83rd Street.

Two cops were sent to the hospital with minor injuries when a livery car slid through an intersection and smashed into an NYPD SUV in upper Manhattan.There was a five-car collision and major backup on the West Side Highway during the morning rush. In the afternoon, the FDR Drive came to a complete standstill as suburban commuters tried to flee the increasingly snowbound city.

The city’s 311 help line had been swamped by nearly 125,000 calls as of 3 p.m. The daily average is only 50,000. Hundreds of callers demanded snow and ice removal, a spokeswoman said.

Emergency calls to the EMS also spiked, forcing longer response times and prompting officials to put on hold callers complaining about illnesses and minor injuries.

Gov. Cuomo declared a state of emergency for New York City, Long Island and Westchester and Rockland counties shortly after 5 p.m.

A Sanitation Department plow operator confirmed that officials were blindsided when the snow began falling in the heart of the morning rush instead of 11 a.m. or noon, as had been forecast.

“It definitely caught us by surprise. This happened three or four hours earlier than we thought,” the driver said. “No one was expecting this.”

Sanitation Commissioner John Doherty, at an evening press briefing, defended the handling of the Upper East Side — claiming that one spreader had a busted GPS and was not reporting progress to the PlowNYC Web site.

He blamed stalled traffic for the lack of plowing in the neighborhood, saying “nothing was moving in the area,” disregarding the reason why.

Meanwhile, in de Blasio’s Park Slope neighborhood in Brooklyn, the mayor’s block was plowed by mid-afternoon.

Neighbor Amber Moran, 21, who works as a nanny, laughed when she heard the Upper East Side remained buried.

“It’s good to see Brooklyn finally getting this attention and not Bloomberg’s neighborhood,” she said.

“I’m glad we’re getting this treatment . . . It’s about time!”

Passengers at local airports were frustrated by the delays and cancellations. “It’s crazy,” said Sheila Fis of Long Island, who was stranded at JFK with her 5-year-old son.

“I’m stuck here for two days. I’m trying to call for a ride back, but no one is willing to drive in this.”

A person walks on the National Mall past the US Capitol in Washington, DC as snow falls during a storm.

Photo: Getty Images

A young boy walks with his mother through Times Square in Manhattan.

Photo: Reuters

Heavy snow falls on New York City on Tuesday as the Polar Vortex descended on the Northeast.

Photo: Paul Martinka

A couple haul their suitcases as they make their way under a snowfall in Washington, DC.

Photo: Getty Images

Construction crews near the Brooklyn Bridge braved the snowstorm to continue work in Brooklyn.

Photo: Paul Martinka

A woman walks in a park beneath the Manhattan Bridge in Brooklyn.

Photo: Reuters

Tourists stand outside of the White House in Washington, DC.

Photo: Getty Images

Robert Burck, also known as the 'Naked Cowboy', performs on the streets of Times Square.

Photo: Reuters

From left, Lindsey Funderburg, Blythe Summers and Isabelle Cosmich, all 17, and visiting from Jackson, Miss., jump in the air as they are photographed by a classmate outside the Basilica of the National Shrine of the Immaculate Conception in Washington.

Photo: AP

Pedestrians trudge through the snow 33rd Street in Manhattan.

Photo: David McGlynn

Sidewalks are cleared of snow and ice in New York City.

Photo: Getty Images

A doorman holds a taxi for his tenants on the Upper East Side during a winter storm which is expected to bring up to a foot of snow.

Photo: Anthony Behar

A woman walks through the snow in Hoboken, New Jersey.

Photo: Reuters

People make their way through Times Square in New York.

Photo: Getty Images

Heavy snow falls on the Brooklyn Bridge Tuesday.

Photo: Paul Martinka

Heavy snow falls on the Brooklyn Bridge Tuesday.

Photo: Paul Martinka

Central Park gets a heavy coating of snow on Tuesday.

Photo: Getty Images

A woman stops to take a picture in the snow in Times Square as the storm bears down.

Photo: UPI

A man dressed as the Statue of Liberty looks to take pictures with tourists in Times Square as snow continues to fall.

Photo: UPI

A tourist puts their dog next to the New York Public Library Lion for a photo.

Photo: Getty Images

A man bikes down a street in New York City as the snowstorm bears down.

Photo: Alberto Reyes/WENN.com

Pedestrians make their way through snowfall at New York's Times Square.